Study On The Technique And Effect Of Rainwater Guidance Infiltration In Sunken-lawn In Road Side-banding

In 2014, the state put forward the concept of "sponge city" and put forward the importance of "infiltration". "Infiltration" use rainwater to replenishment groundwater resources, rainwater resources is a critical point, especially for lack of water in Northwest. Urban road produce huge runoff in the process of rainfall, set LID measure such as sunken-lawn in the road side banding to reduce surface runoff, replenishment of groundwater correspond with the sponge city construction. While Xi’an is located in loess areas, especially the existence of collapsible loess, so that there is a risk of seepage here.In this paper, the regularized infiltration protection system of rainwater is proposed, and the appropriate model software is selected by means of experiment and software. Based on the data of self-recording rainfall in Xi’an from 2005 to 2014, the sunken-lawn in road side-banding is analyzed in different road with different impervious structure and depth of sunken. The influence of the difference of rainfall intensity on the accumulation of subsidence and the amount of seepage in the lower part of the road, and the influence of the difference of rainfall intensity on the change of water content in the lower part of the road. The most suitable side of the sunken-lawn in road side-banding of the rain under the regularized infiltration protection system.(1) It is proposed that the rainwater regularized protection system in sunken-lawn with anti-seepage structure in road side-banding, regularized protection systems have a clear role in guiding.(2) Compared with the measured and simulated moisture content values in experiment box, Simulation is trustiness. The spatial distribution of soil moisture is right, indicating that the established two-dimensional model, initial conditions and boundary conditions are suitable for soil infiltration process in sunken-lawn in road side-banding, which can be simulated by HYDRUS-2D/3D.(3) Compared with the same anti-seepage structure, the variation soil moisture content and the change of water content are obtained. With the increase of the depth of subsidence, the amount of water infiltration increases, and the amount of water infiltration is different. The amount of seepage increases with increasing depth.(4) The difference of water content at the observation point on the side of the impervious structure is compared with that of the different depths and the different impervious structures in the three kinds of rainfall scenarios. 60 °, for the different depth of the recess can be a comprehensive anti-seepage, with good protective effect.(5) The choice of depth of sunken-lawn consider the total amount of sunken-lawn is too large, and the depth is too small make a little rainwater infiltration return to the underground, so the depth is not more than 10cm impermeable structure on the road.The influence of the lower soil moisture content is small, and the rainwater can be maximized to return to the ground, while the loess of the roadbed structure below the road is prevented from collapsible loess.